The Honeywell RWD42 water defense water-sensing alarm offers superior protection against leaks and water damage near potential trouble spots close to plumbing around the home or office. Patented 5-foot cable solution extends the detection zone offered by traditional spot detectors by 3100%. Additional cables (sold separately) can be connected to extend the cable and increase water sensing area up to 240 feet. Water Sensing Cable detects water on entire length of cable. Place the cable in spots where you do not usually observe such as water heaters, sump pumps, under sinks, around toilets, behind washing machines and dishwashers. This is the only system that can run around the entire perimeter of a room or basement. This unit also gives off a chirp sound when the battery is low. The detector can be placed flat on the floor or mounted on a surface, for wall mounting, use double-sided tape (included) to adhere to a dry surface. This unit works directly out of the box with no assembly required, simply add batteries and place in the desired location where you want to prevent water damage.